package day14;

/**
 * @author oldliu
 * @since 1.0
 */
public class ForTest8 {
    public static void main(String[] args) {
       // System.out.println(Circle.PI);
        Circle c=null;
        //System.out.println(c.r);肯定nullpointerexception
        System.out.println(c.PI);
    }
}
